Holding on to excess energy is the solution to the problem of supply meeting demand
Managing the electrical supply grid is a constant battle to balance demand against supply.
Too much power, and you must dump power to other jurisdictions at fire-sale prices; but too little to meet demand and you're buying back from those same sources at inflated prices.
The solution seems disarmingly simple: What if you could capture the excess power on days you'd normally sell at a loss and then redeploy it on those days when demand is high and supply is falling short?
It's not (yet) as easy it sounds, but it is becoming viable with a variety of innovative technologies, much of them being invented and built in Ontario.
"Storage facilities on the grid are a real game changer," Bruce Campbell, president and CEO of Independent Electricity System Operator in Ontario, said in July, announcing four pending contracts for 34 megawatts of storage to add to two existing storage facilities that total 6 megawatts. "Our electricity system was built on the concept that you can't store large amounts of electricity – we produce electricity at the same time as we consume it. Energy storage projects provide more flexibility and offer more options to manage the system efficiently," Campbell said.
"A lot of this technology is not new, it's been around for decades," says Daryl Wilson, CEO of Hydrogenics, a global designer, manufacturer and installer of hydrogen fuel cells based in Mississauga whose roots date back to the 1950s, which has won a contract to supply a 2 Mw system. Hydrogenics's modular fuel cells are about the size of a beer fridge and turn one megawatt of electricity into 500 kilograms of hydrogen.
Instead of being used directly to create electricity, the hydrogen is bottled and used to power fuel cells in vehicles such as buses or forklifts. It can also be mixed into the natural gas supply – much as ethanol is added to gasoline – to fuel natural gas generators and other gas appliances.
"Think of the pipeline as a storage facility for energy on demand," says Wilson, noting that its potential as a natural gas additive is the reason why Enbridge partnered with Hydrogenics.
Northland Power is another suitor for an Ontario contract and plans to leverage a played-out iron ore mine in Marmora, near Peterborough, Ont.
John Wright, executive director of business development, envisions a $700-million project that pumps water from one reservoir to a second reservoir at a higher altitude, absorbs excess from the system and then releases it to drive two turbines generating 400 megawatts for five hours on demand. By throttling the water the turbines could be configured for 200 Mw for 10 hours or 100 Mw for 20 hours, as demand dictates.
Northland, which has billions of dollars in offshore power projects in hand, wants to re-landscape the waste rock around the open pit, turn it into a reservoir and create a second reservoir above it. "The drop would be four-to-five times that of the Horseshoe Falls at Niagara," Wright said. "The transmission lines are only eight kilometres away. It's an ideal location." Wright said it would be the largest of its kind in Canada.
There are other innovations in the pipeline:
• Temporal Power of Mississauga has a flywheel technology that absorbs the peaks and valleys of electricity generated from wind turbines and stabilizes the grid. In the design, a motor spins a solid steel flywheel when the wind is strong. When the wind fluctuates and the grid voltage drops, the flywheel's inertia drives the motor, which acts as a generator to send power back to the system. It does this in short alternating cycles several times an hour in concert with the wind speed. Temporal president and CTO Jeff Veltri is an engineer who invented the technology and built the first prototype in his garage in 2009. It is 85-per-cent efficient, he says, and the 500 Kw modules can be stacked and scaled as needed.
• Chemical battery technology: Hydro Quebec's R&D arm, IREQ has developed a lithium iron (not to be confused with lithium ion) phosphate battery, which Renewable Energy Systems Canada in Montreal has built into a 4 Mw storage unit and which will come on line this year. Unlike lithium ion batteries, the newer technology has a faster charge rate, more consistent discharge and much longer life cycle.
• One of the more unusual: Hydrostor's Underwater Compressed Air Electrical Storage (CAES), which converts electrical energy into compressed air. They are putting the final touches to a pilot project that would sink a giant air tank 80 metres into Lake Ontario and use water pressure to push the air back up on demand to expand and drive a generator.
For more innovation insights, visit www.gereports.ca
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